The present invention relates to a vector access control system for a computer system. The system according to the present invention is used, for example, for controlling the access to vector data in a main storage relating to a vector unit in a supercomputer system.
A method of indirect address access has been used in a vector unit in a computer system where an access to a main storage is carried out by the designation of an index address for a leading address (or a base address). Generally, the main storage has a bank structure consisting of a plurality of banks, to increase the access speed, and accordingly, a plurality of data buses are connected with the main storage.
Indirect address data are read, per unit of plural sets of indirect address data, from the vector register, and a target address is produced by adding the read indirect address data to the leading address. The produced target address signal is then applied to the main storage so that the access processing is carried out.
For a "load" access operation, vector data are read in parallel from the banks of the main storage, by using the above-mentioned plural target addresses, and for a "store" access operation, vector data are written in parallel into the banks of the main storage, by using the above-mentioned plural target addresses.
It is assumed that vector data access requests with the indirect address method are simultaneously carried out by using a plurality of indirect addresses, for example, 4 indirect addresses, with respect to a main storage having a bank structure of, for example, 256 banks. If vector data are located at random in the main storage, a situation can occur in which a plurality of data in question, for example, data a.sub.1 and data a.sub.2, are located in the same address. In such a situation, a problem arises in that a bank conflict between the accesses to the main storage will occur, the access for the later data (for example, data a.sub.2, if data a.sub.1 is accessed with priority to data a.sub.2) is delayed, and the efficiency of the access operation is deteriorated.